
% Specify the types of various objects

:- add(block(a)). 
:- add(block(b)). 
:- add(block(c)). 
:- add(block(d)). 
:- add(hand(h)). 
:- add(table(table)).

% Invert blocks in an existing four-block tower

:- add(task(invert_tower([a, b, c, d]))).
:- add(on(a, b)). 
:- add(on(b, c)).
:- add(on(c, d)).
:- add(on(d, table)). 
